Vertically adjustable seat



Sept. 9,

N. T. SHEPHERD VERTICALLY ADJUSTABLE SEAT .Filed April 23, 1942 s Sheets-Sheet i herd P 1947. N. T.ISHEPHERD 2,427,234-

'VERTICALLY ADJUSTABLE SEAT I Filed Apz 'il 25, 1942 3 Sheets-Sheet 2 hue/22 0f N. 'r. SHEPHERD VERT ICALLY ADJUSTABLE -SEAT Sept. 9, 1947. 2,427,234

- Filed April 25, 1942 5- Sheets-Shec :s

, I fizveizior ZSizepkerd rugs.

Patented Sept. 9, 1947 UNITED STATES PATENT OFFICE 2,427,234 VERTICALLY ADJUSTABLE SEAT Na'tha-niel'T. Shepherd; Salt Lake City, Utah Application April 23, 1942, SeriaLNo. 440,145

1 Claim. 1

The invention. relates generally 'to posture chairs and more particularly to improvements in vertically adjustable seats- The so-called posture chairs used. extensively in clerical ofli'ces, schools. eto are characterized by the adjusta'bility of the seat for depthxand height and of the backcrest for height and-angle. 'Heretofore such chairs have been commonly made entirely offmetal except for the seat cushions. Having in view :the current severe restrictions on the use of metals tin articles of the class under consideration, one object of the present invention is to provide a chair ofsubstantially all wood construction which has the usual features of adjustment of the metal posture chairs but in which the use of metal is reduced'toa negligible amount.

Another object is to'providenovelseat-adjusting means particularly:suitable for chairs of 'wood construction whereby the seat'may be quickly and accurately adjusted for height and for'depth.

Another object is to provide a cushioned seat chair of novel and improved construction adapted for the use of removable seat covers andin which the seat portion may be readily detached for replacement'of the cushion or-cover.

Another object is to provide an improved height adjusting mechanism particularly suitable for chairs of wood construction which mechthe chair.

anism is eificient and reliable in action yet extremely simple and inexpensive to'manufacture and which requires relativelylittle metal in its construction.

Other objects andv advantages of the invention will become apparent from the followin detailed description of the preferred embodiments illustrated in the accompanying drawings in which: 7

Figure 1 is a front elevational view of a chair having a vertically adjustable seat-embodying the features of the invention.

Fig. 2 is a fragmentary verticalsectional view of the chair taken substantially along the line 22 ofFig. 1.

Fig. 3 is a horizontal sectional view of the chair taken substantially along the line 33 of Fig. 2. I

Fig. 3a is a fragmentary bottom view of the seat assembly.

Fig. 4 is a verticalsectional view-0f the chair seat and base takenalong the line 4--4 of Fig.3.

Fig.5 is afragmentary vertical sectional view of the chair base. taken'along the line '5-5 of Fi .3.

suited-for use in so-called posture chairs.

Fig. 11 is a fragmentary vertical sectional view of the -modified form of chair taken "along the linel l-H of Fig. 10.

Fig. 12- is afragmentary vertical sectional view ofthe-chair taken=alongstheline 'l'Z-I 2-of-Fig. 10.

-While .the invention in its broader aspects is adapted .foruse in varioustypes-ofehairs; certain; of.- the important features are especially The invention, has therefore beendisclosed as-embodied: ina-chair. of-this character for purposes of-illustration. Itis tolbe understood, however, that various changes, modifications and adaptations may be-madein theform, construction and arrangement of the parts without departing from the spirit and scope of the invention as expressedinthe appended-claim.

Referring now to-Fig.. 1.. of the drawings, the preferred form of chair selected-to illustrate the invention comprises generally a-base l-iadapted to be supported 0n the floor, a seat assembly 16 adjustably mounted on the base, and a back rest .L'l .adjustablycarried on an upright back frame extending upwardly from the base- The framework of the chair is constructed substantially entirely of .wood or like material except for-the cushions and covers and the fittings; such-as bolts and. screws,.for=connecting the various parts subject to the greatest strains. Moreover, the parts have .been constructed. and arranged to use only the simplest types of fittings andonly those essential for the-proper functioning of the chair structure. .In this way, themetal. requirements of the improvedchair have beenv reducedtoa negligible amount.

As willbe seen by reference to-Figs. 1,2:and3, the base =15 comprises a generally rectangular box-like section formed by a bottomv plate 20 to which. fourv supportinglegs Zlare rigidly secured asby screws 22.. The legs-are. equipped with. conventional casters 23. Preferably, the legs are bowed; outwardly .to provide a greater spread at their point of contact with the floor and thus increase the stability of the chair.

Rigid with the bottom plate 20 are a pair of upstanding side members or panels 25 spaced apart on opposite sides of the bottom plate and arranged in substantially parallel relation. A back panel 26 and a front panel 2'! close the front and rear ends of the box-like section of the base. The back panel 26 is rigidly secured in place while the front member 21 is removabl mounted for reasons to appear presently.

The seat assembly, as herein shown, comprises a fiat cushion supporting member 28 of generally oval contour as shown in Fig. 3a. A cushion or pad 29 of resilient material is positioned'on the top of the member 28 and is enclosed and held in place thereon by a cover 30 of any suitable material adapted to have its marginal edge portion turned under the supporting member. The said edge portion of the cover may be formed with a hem or casin 3| through which a gather-cord 32 may be drawn to stretch the cover tightly over the cushion and to hold it securely in place.

The seat assembly is adapted to be supported on the base for adjustment vertically, that is, for height, and from front to rear, or for depth, by supporting and guiding means of novel construction. The supporting and guiding means preferably comprises coacting elements in the form of parallel guide elements or tongues 33 rigid with but spaced downwardly from the seat member 28 and adapted to slidabl engage in grooves 34 formed in the inner faces of the side panels 25, as best shown in Fig. 4. As herein shown, the tongues 33 are formed on the lower outer edges of a pair of supporting members 35 rigidly attached to the underside of the cushion supporting member 28 in laterally spaced relation. The members 35 are l substantially shorter than the cushion supporting member 28 and are set inwardl from the front and side edges thereof so as to leave a part of the marginal edge portion of the member unobstructed for the reception of the seat cover. The members, however, extend substantially to the rear edge of the supporting member and suitable notches or slots 36 are provided therein for the reception of the seat covers. These slots are preferably dimensioned to receive the edge of the seat cover with a tight frictional fit and are thus effective to hold the cover against displacement with respectto the cushion 29.

As will be seen by reference to Figs. 3 and 4, the members 35 are spaced apart so as to fit snugly between the side panels 25 with the tongues 33 entered in the grooves 34. To provide for vertical adjustment of the seat assembly, a series of such grooves are formed in each panel 25, the grooves being spaced apart vertically of the panel and arranged to present opposed pairs on opposite sides of the base. A reinforcing member 38 connected between the lower edges of the members 35 serves to hold the members rigidly in predetermined position with the tongues 33 properly spaced for coaction with the grooves 34.

With the supporting and guiding means above described, the height of the seat cushion may be adjusted as required by engaging the tongues 33 in any selected pair of the grooves 34. When it is desired to transfer the seat assembly from one pair of supporting. grooves to another, it is necessary first to remove the front panel 21 ofthe base so. that the tongues may be withdrawn from the grooves .in which they are currently entered. To permit such removal, the front panel is formed with tongues 4| at each end engageable in vertically disposed slots 42 in inner faces of the side panels 25. These slots are terminated substantially above the bottom edge of the side panels and the tongues 4! are similarly dimensioned so that the panel is supported thereby independently of the bottom member 29. When the panel is in place, it serves to confine the seat assembly within the box-like base. In other words, the front panel performs the dual function of limiting the forward movement of the seat assembly and enclosing the front of the base to give it a neat and attractive appearance.

While the seat assembly is confined within predetermined limits by the front panel of the base and the back frame of the chair, a substantial range of movement is permitted by reason of the fact that the supporting members 35 are substantially shorter than the grooved side panels 25 with which they coact. Thus a substantial range of adjustment for depth, that is, adjustment of the seat assembly from front to rear, is permitted. The seat assembly may be locked in any adjusted position by means of a set screw 43 or the like threading into one of the side panels and engaging the companion supporting member of the seat assembly. Ordinarily it will be found desirable to dispense with the use of the locking screw since the frictional resistance of the interengaging tongues and grooves is sufficient to prevent sliding of the seat when the chair is occupied. However, instant adjustment of the seat may be effected by simply relieving the seat of the weight of the user and shifting it either forwardly or rearwardly as desired. This can be done very conveniently by gripping the edges of the seat in the hands while partially rising from the sitting position.

Rigid with the base I5 is the back frame of the chair on which the back rest I1 is carried. The back frame, as herein shown, comprises a pair of upright members 45 and 45 rigidly anchored to the base in any suitable manner, preferably at the rear corners thereof as shown in Fig.- 3. In the particular chair illustrated, the side panels 25 and the rear panel 26 of the base are mortised into the adjacent sides of the members 45 and 45 to provide a strong and rigid frame structure. A cross bar 41 connected between the upright members intermediate their ends serves to reinforce the back frame and to hold the members in fixed spaced relation. The back rest IT in its preferred form, as shown in Figs. 1, 2 and 6, is of simple yet rugged construction. In the form illustrated, the back rest comprises a back plate 50 of wood or like material of generally oval contour bent to present a concave front surface and convex rear surface as shown in Fig. 6. A cushion or pad 5! of suitable resilient material is mounted on the front or convex face of the member and is held thereon by a removable cover 52. This cover is preferably of the type having a marginal edge portion adapted to fit over the edges of the back member and is desirably formed with a hem or casing 53 through which a draw-cord 54 may be threaded to hold the cover in place.

The back member 5!) is suitably secured as by bolts 55 to a cross member or swivel bar 55 adapted to be pivotally supported between the upright members of the back frame. The swivel bar is preferably formed with an arcuate or concave recess 51 dimensioned to receive the convex face of the back member 50 and to provide a relatively long bearing surface effective to prevent warping of the member or other change from its arcuate bar fifi is adapted to be d'etachably securedz'bev tween theuprig'htmembers 45- and 43in any selected one of a'plurality of 'verticallyspaced positions: T6 this endthe upright members are formed with a seriesof vertically spaeedrecesses 58*and' the swivel bar EEiisproVided atea'ch end with projectingpins 59 and 269" of wood, metal or other suitable-material adapted-to engage in said recess-est The pin 59 is preferably fixed while pin 69 isconstructed 'ir-ithe form of a plunger adapted for retraction axially to withdraw it from the recess wherebythe entire back rest assembly may be tilted to withdraw the companionpin from its recess. To this end the pin =fifl ls slidably supported in a suitable-bore 6 and a spring 62 insertedin'the bore actsagainst the inner end of-tlrep-in to urgethesame outwardly. An arm 6'3-,"threade'd into or'otherwise suitably secured'to l the pinand projecting laterally therefrom through a slot 64 in the swivel-bari ii serves to limit the outward movement-of the pin and'provides a convenient manually operable means by which the pin may be retracted from the recess in whichitis fitted.

The mounting of the back rest on the frame by means of the pins 59 and 6b, as above described, in addition to permitting convenient adjustment'ofthe back rest for height also permits the swiveling ofthe rest about a horizontal axis. Thus the rest-is readily shiftable to the desired angle bypressure of the back of the person sitting in the chair. The weight of the cushion. tends to rock the back rest into a horizontal position but such movement is limited by the cross bar ti which'acts asa-stop for the rest. For this purpose, the bar is adaptedto coact' with the lower edge of the back rest in any of its adjusted posi-.

tions to hold the same in-a substantially vertical which is advantageous under some conditions of use. In general, this chair utilizes the same back rest ll andthe same seat assembly Hi. In this instance, however, the base is simply aflat, generally rectangular top member 15 of wood or other suitable material towhich the legs 2! are attached.

Adjustable support for theseat assembly isprovided'by a'seat frame H supported on the base torotate-or' swivel about a'vertical axis. The seat frame l'l, as shown in Figs. 7-9, comprise-5a bottom plate 'l2 with upstandingaside panelslii at each side edge. A back panel-M- and a frontpanel 15- are assembled therewith to form an: op tODBBd'bOX-llke structure of generally rectangular form.-- Side members 45 and' iB of 'theback frame are-mortised or otherwise rigidlyjoined to thesideand back panels of theseat frame at the rear corners thereof, asshown-in Fig. 6.

The side panels 13' are similar in general to ac panels25jpreviously'described, in that they Y are-provided with. one OIT 'mOI'GLSGtS of horizontally disposed :grooves: 16: for: slidably. receiving: the tongues 33 of:'the'seatiassembly it, which, as statedi above, maybe.- identical. withv that previously described. Alsingleigroove 'lfiis shown in Figs: 7 ends by Y way of illustration; thus providin'g: depthiadju'stment of the seat while adjustment i for height is obtained through i the swivel mechanism;.asi wilt.lappeart presently. It will be understood; of course, that a plurality of the grooves l'li may be provided similar to the grooves 34;- thus giving .Wider' range of. adjustment for height'-;than' is obtainediby the swiveling mechanism :alon'e:

Regardless: of the. numb'err of grooves it provided in the seat frame panels, the frontpanel i5 is assembledlitherewitht so that it may be removed to ipermitiwithdrawal of theseat assembly for replaeement oi the; cover or other purposes; To thisiendxthe panel 15 is formed with tongues ll at eaclr'end adapted. to slidably engage. vertically-disposed slots: 78 inrthe sid panels was shown in: Fig-. 9 The tongues and notches are terminated sub'stantially above the lower edges of the respective members; as shown in Fig. 7, so that the weight oi thepanel member is carried on the tongues: Withthis arrangement'the panel member may be extend-edover the front edge or the bottom ursued conceal the same and thus en hance-tlieappearance of'the chair structure.

Themechanismwhich" provides the swiveling action also provides for the adjustment of the seat vertically-: Thismechanism, in the preferred form=illustrated inFigs. 7-9, comprises an externally 'screw threaded member 36 having in" tegral peripheralflange Bl'at its upper end, The flange provides a bearing of substantial area and may 'be attachedto the bottom plate '52 of the seat 'frame-asbywood screws 32; The member Sa ls adapted to engage in-a companion internal ly threaded member in the form of a sleeve or bushing 83 fitted in-an aperturefi i in the top member Hi fl'the base. The bushing is formed with a peripheral fiangeiifi adapted to rest on the topmember andit may be secured in place thereon by-means of "wood screws 86.

Preferably the-threaded member and the cooperating bushing are of relatively large diameter to provide firm support for the seat. The length oi the threaded member is determined by the rangeof vertical adjustment required. Thus when a' -substanti'a'lportion of'the adjustment is obtainedthrough the medium of the tongue and groove mounting of the seat assembly on the seat frame, the threaded member may be relatively short, thus reducingthe'amount of metal required mtne c'onstruction-ofthe chair. On the other hand; the-provision of-a single groove for mounting the seat assembly will necessitate a somewhat longer threaded member to obtain the necessary rangeof adjustment.

Inorder to prevent undesired raising of the seat and possible disengagement of the threaded menrb'ei' flil -fromits socket by inadvertent rotationtot thesea't irame and additionally to maintain': the seat in predetermined relation to the base; I provide means'for limitingthe range of rotation of the: seat frame with respect to the base. This means, of course, is constructed so as tobeireadilyreleasable and thus permit of adjus'trnent'. when: requiredi As herein shown, means provide'd 'for this purpose comprises a headed"bolt: 8'1 anchored in the top member it! of theb'aseand arranged to project through an arcuate slotiwiin tlre bottom plate 12 of the seat frame. It will be appreciated that s1ot'88 may be formed in the top member 10 of the base, if desired, in which case the bolt 81 will be anchored to the bottom plate 12 of the seat frame. With this arrangement, limited swiveling of the seat is permitted yet the seat is always held in a forwardly facing position so that the supporting legs do not interfere with the proper use of the chair, Moreover, by simply removing the bolt 81, the seat frame ma be turned for raising and lowering as required. Access to the bolt for removal is readily obtained by sliding the seat assembly to the forward position or, if desired, the seat assembly may be removed from the chair by simply sliding it out of the supporting grooves as previously explained.

The second modified form of chair shown in Figs. 10, 11 and 12 differs from the previously described swivel chair in that vertical adjustment is obtained solely through the use of combined swiveling and height adjusting mechanism, while depth adjustment is obtained in simple and efiicient manner now to be described. Referring to Figs. Ill-12, the seat frame H of the chair is similar to the seat frame H except that side panels 13 instead of being horizontally grooved are formed with a series of horizontally spaced vertical notches 99 in their inner faces. Seat assembly I6 is similar to the seat assembly '6 except that the supporting members 35' are formed with outwardly facing vertically disposed ribs 9| instead of horizontal tongues. The ribs 9! are dimensioned to fit into the notches 90 and thus locate the seat assembly with respect to the seat frame, the seat assembly resting on the bottom plate 12 of the frame. It will be evident that the seat assembly may be set in any one of a plurality of horizontally adjusted positions by simply lifting the tongues 9| from the notches and reinserting them in a different selected set of the notches.

The swiveling and adjusting mechanism of this chair may be exactly like that previously described except that in this case it may be desirable to employ a somewhat longer threaded member 99' to provide the range of adjustment required. Undesired rotation of the seat frame is prevented by limiting means similar to that described hereinbefore.

It will be apparent from the foregoing that the invention provides a posture chair of novel and improved construction. Although constructed substantially entirely of wood, the chair embodies all the advantages of adjustability usually found only in all-metal chairs, The metal required for th construction of the improved chair has been reduced to a negligible amount which is an extremely important consideration when conditions necessitate restricted use of metals for products of the class under consideration.

Adjustment of the seat for both height and depth is readily attained through the medium of the novel seat supporting and guiding arrangement provided by the invention. Moreover the seat may be readily removed from the chair for recovering or other purposes. Removable covers of the draw-cord type are employed and these covers are securely held against displacement when the chair is in use.

The chair also comprises a novel swiveling back rest which is readily adjustable both for height and for angular position independently of the seat adjustments. By reason of the novel construction employed, the parts ar securely held against warping or any other changes from the initial form provided, The novel form of the back rest also facilitates removal and replacement of the cover.

The invention further provides a novel swiveling and height adjusting mechanism particularly suitable for use with chairs of wooden construction. This swiveling mechanism requires relatively little metal in its construction, the advantage of which will be readily appreciated. Undesired changes in the seat height and disengagement of coacting parts is prevented by limiting the swiveling movement of the seat in the normal use of the chair, while provision is mad for temporarily removing these limitations when it is necessary to adjust the seat. Adjustment for depth of the seat, that is, adjustment of the seat from front to rear with respect to the base of the chair, is obtained in a simple and effective manner without the use of complicated mechanisms or metal fittings.

In general, chairs constructed in accordance with the present invention are strong and sturdy and well adapted to perform their intended function. Moreover, the chairs are attractive in appearance and well suited to use in modern ofiices, schools and the like requiring posture chairs of this general character.

I claim as my invention:

In a chair structure, in combination, a base, a seat member, means supporting said seat member on said base for vertical adjustment and for front to rear adjustment in a horizontal plane, said supporting means comprising a pair of elongated supporting members rigid with and depending from the seat member adjacent opposite sides of the same, outwardly facing elongated guide elements extending along the lower edges of said supporting members, said base including a pair of upright side panels paced apart to receive said supporting members with a relatively snug fit, each of said side panels having a series of horizontally disposed grooves adapted to slidably receiv said guide elements and spaced apart vertically to provide a plurality of adjusted positions for said seat member, and front and back end panels extending between the front and rear ends of said side panels to close the ends of said grooves and to define the forward and rearward adjusted positions of said seat member, one of said end panels being removable to permit transfer of said guide elements from one set of grooves to another for vertical adjustment of the seat member.

NATHANIEL T. SHEPHERD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,065,280 Stanger et al. June 17, 1913 374,175 Davis Dec. 6, 1887 2,061,163 McCall Nov. 17, 1936 1,016,763 Nil] Feb. 6, 1912 182,553 Fuhrmann Sept. 13, 1892 632,775 Bolens Sept. 12, 1899 12,972 Stratton May 29, 1855 1,326,417 Paine Dec. 30, 1919 542,956 Feely July 16, 1895 1,237,956 Pue Aug. 21, 1917 1,293,530 Parker Feb. 4, 1919 2,054,557 Cramer et al Sept. 15, 1936 (Other references on following page) Number Number Number Name Date Bishop June 6, 1939 Bobrick June 25, 1895 Haffner Jan. 14, 1930 Moore Jan. 1, 1884 Knaur et a1 Feb. 5, 1929 Saxe Apr. 25, 1876 FOREIGN PATENTS Country Date England Sept. 29, 1908 

